Can we try and cast all these into the same sentence form?  I think description-of-new-facility is the right way (rather description-of-change which we use for bugs + 'incompatible changes').
So rewrites e.g. like these...
  * A new utility function makes it easy to "shortcut" slow calculations or file loads...
   * **New utility function for "shortcutting" slow calculations or file loads**...
  * Load reduced latitude/longitude or Gaussian gridded data from GRIB1 or GRIB2.
   * **GRIB loading supports reduced grids (latitude/longitude or Gaussian, GRIB version 1 or 2).**
  * A new utility function to assist with caching.
  * Extend RMS analysis to perform a weighted collapse.
   * **The :data:`iris.analysis.RMS` aggregator supports weighted operation.**
  * A new experimental function to equalise cube attributes.
  * Mask collapsed result based on a missing-data tolerance.
   * **:meth:`iris.cube.collapse` provides missing-data masking with a tolerance level.**
  * Ability to load NAME vertical coordinates.
   * **NAME loading supports vertical coordinates.**